Guideline light



y 1942- A. ca. CARTER 2,291,152

GUIDELINE LIGHT Filed March 4, 1940 2 Sheets-Sheet l \nvenov Andrew G.Qar fer 11 I srm I July 23, 1942.-

A. G. CARTER GUIDELINE LIGHT Filed March i[mllllllllllfllllllllllllllllfllllllilllll 2 Sheets-Sheet 2 \hvenTorAnchgw G. Cafl'er Arfomei;

Patented July 28, 1942 UNITED STATES PATENT OIFFICE Application March 4,1940, Serial No. 322,100

7 Claims.

This invention relates to guide-line lights. A device of this kind isfor the purpose of aiding a sawyer to guide his work into such a machineas a straight-line ripsaw to avoid knots and other defects in the board.

Although the device may find other uses it is particularly intended tobe used with ripsaws in trimming defects from boards and in doing thiswork it is desirable to saw as close to the defects as possible toprevent waste of lumber.

The guide-line light is supported above the feed table of the saw andcasts a narrow elongated shadow on the table or the work upon it whichshadow is accurately in line with the saw and the shadow cast upon thework indicates accurately the path of the saw as the board passesthrough the machine.

The invention includes such improvements as an improved light bulb inwhich the elongated filament is under constant tension so that it willbe maintained straight at all times. The filament is located close toone surface of the elongated light bulb so that it may be brought asclosely as possible to the lens. A lens is provided so shaped that itwill project the light rays passing through it in parallel pathsincreasing the intensity of the light and sharpness of the shadow. Awire or other elongated object is located in the paths of the light raysthat have passed through the lens and casts its shadow upon the work.

The invention provides other novel features of construction andarrangement as hereinafter more fully described and particularly pointedout in the claims, reference being had to the accompanying drawings, inwhich:

Fig. 1 is a perspective view of a device embodying this invention shownin association with a part of a ripsaw, a board and a sewer at work.

Fig. 2 is a transverse sectional elevation-of the device.

Fig. 3 is a longitudinal sectional elevation of the device. I

Fig. 4 is an enlarged sectional elevation on the line 4-4 of Fig. 3, and

Fig. 5 is an enlarged sectional elevation on the line 5-5 of Fig. 4.

Like reference numbers refer to like parts in all the figures.

l indicates suitable framework by which the device may be adjustablysupported on any convenient object 'such as the ceiling of the buildingor upon framework built especially for that purpose. 2 is the housingmounted on the framework l and preferably of elongated talight from thebulb being lost within the chambet 5. The light rays indicated as 9passing through the lens 8 are caused to travel in parallel paths inwhich the shadow casting wire is located thus concentrating the lightand increasing its brilliancy on the work and also clearly defining theedges of the shadow. The sawing machine is indicated at H] and l I is aboard to be sawed and i2 indicates the straight-line shadow cast uponthe board.

In order to make the shadow clear and well 7 defined the elongatedfilament I3 m the light bulb should be kept perfectly straight and inalinement with the shadow casting wire 3. This filament is kept straightby attaching one end to a fixed electrode id in the tube l5 and byconnecting its other endwith a spring tensioned electrode I6. Thisspring tensioned electrode is held under tension by flexible springs I!connected with a second fixed electrode l8 within the tube l5.Therefore, expansion of the electrode .when heated which wouldordinarily'cause it to droop between its connections is overcome by theflexible mounting which maintains it straight and under tension at alltimes.

For greatest efliciency it is desirable to brin the filament of the tubeas close to the lens as possible and therefore it is mounted close toone side of the tube I5 which side'is located adjacent the lens 8. It isalso desirable to provide a universally adjustable socket for mountingthe tube i5 so that the filament may be alined longitudinally with theshadow casting wire 3 and may be positioned accurately over the centerof the lens 8 both by rotation and lateral movement. The tube socketcomprises a socket 20 in which the tube is mounted in aconventionalmanner such as by a screw threaded base and it has theconventional circuit carrying contacts. v This socket 20 has a band 2|surrounding its periphery, the surface of which is arc-shaped. A base 22is provided which has a split clamping portion 23 with a clamping bolt24 which clamping portion surrounds the band 2| and holds it in itsproper pered shape. The shadow casting wire- 3 is adjusted position.This clamping means permits elongated filament I3 is directlyoverthecenter of the lens I and in longitudinal-allnement with the shadowcasting wire 3.

In operation after the tube It has been properly adjusted as abovedescribed, it is energized and the light rays from its filament l3passing through the elongated opening I and through the lens 8 whichdiverts them into parallel paths which pass the shadow casting wire Iand cast a pronounced straight-line shadow I2 upon the work I i which ismanipulated by the workman upon the table of the sawing machine It. Thedevice is so adjusted that this shadow is in accurate alinement with thepath that the saw will follow when it passes through the machine andtherefore the sawyer can shift the work to a position where the saw cutwill remove defects from the board but will saw so closely to thedefects that material will not be wasted.

By locating the filament I! close to one side of the tube 6 it may bebrought close to the lens I for greatest eificiency and the lensconcentrates the light rays and intensifies the light and consequentlythe shadow cast upon the work so that the device may be used in a welllighted factory with thorough success. The lens also confines the lightrays in straight parallel paths which clearly define the outline of theshadow.

The invention is defined in the appended claims and is to be consideredcomprehensive of all forms of structure coming within their scope.

I claim:

1. A device of the class described comprising an elongated straight-lineshadow casting element, illuminating means for casting a. shadow by saidelement associated therewith and spaced therefrom comprising, anelectric light tube having an elongated lighting filament and a lensadjacent said tube shaped to direct light rays passing through it intoparallel paths said parallel paths continuing past said shadow castingelement and to the object onto which the shadow is to be cast.

2. A device of the class described comprising an elongated straight-lineshadow casting element, illuminating means for casting a shadow saidelementassociated therewith and spaced thereirom comprising an electric.light tube, a lens adjacent said tube and an elongated lighting filamentin said tube located close to the side thereof which is adjacent andparallel to said lens, said lens being shaped to direct light rayspassing through it into parallel paths past said shadow casting element.

8. The elements in combination defined in claim 2 combined with meansfor maintaining said lighting element under constant longitudinaltension.

4. The elements defined in claim 2 combined with an adjustable mountingsocket for said tube having means for rotatably adjusting said tube andmeans for angularly adjusting said tube with respect to the longitude ofsaid filament.

5. A device of the class described comprising, an elongatedstraight-line shadow casting element, illuminating means for casting ashadow by said element associated therewith and spaced therefromincluding, an electric light tube having an elongated lighting filament,means for constantly maintaining said filament under 1ongitudinaltension, and a lens adjacent said tube shaped to direct light rayspassing through it into parallel paths past said shadow casting element.

6. A device of the class described, comprising, an elongatedstraight-line shadow casting element, illuminating means for casting ashadow by said element associated therewith and. spaced therefromincluding, an elongated electric lighting element, an adjustablemounting socket for said lighting element having means for adjustingsaid element angularly with respect to its longitudinal dimension, and alens adjacent said lighting element shaped to direct light rays passingthrough it into parallel paths past said shadow casting element.

7. In a device of the class described, a shadow casting element, a lightbulb associated therewith, an enclosed chamber within which the lightbulb is located, a slot in the bottom of said chamher, an elongatedfilament in said light bulb located parallel to said slot, said filamentbeing located at a side of said bulb closest to said slot, and a lensadjacent said slot to receive light rays passing through it and convertthem into parallel paths for casting ashadow from said element.

ANDREW G. CARTER.

